Some techniques for displaying simulated airport visual approach glide slope indicators on aircraft cockpit displays are known. Two examples of such techniques are disclosed in U.S. Pat. No. 7,216,069 issued to Hett (hereinafter “Hett”) and U.S. Pat. No. 7,209,053 issued to Gannon (hereinafter “Gannon”), both of which are incorporated herein by reference in their entirety. As described in Hett and Gannon, aircraft landing at airports during marginal Visual Meteorological Conditions (VMC) or in situations where there are reduced visual cues (e.g., night flights) are aided by an Instrument Landing System (ILS). An ILS provides a radio beam that originates on the ground at an ILS-equipped airport and generates a glide slope that an aircraft can follow during an instrument approach to the runway. The ILS radio beam is detected by equipment onboard the aircraft and provides lateral, along-course, and vertical guidance to aircraft attempting to land at that airport.
However, some airports do not have an ILS-generated radio glide slope and those that do may, nevertheless, wish to provide additional landing aids. Accordingly, airports may substitute for an ILS and/or provide airport lighting aids in addition to the ILS, as described in the U.S. Federal Aviation Administration's (FAA) publication entitled “Aeronautical Lighting and Other Airport Visual Aids.” The airport lighting aids may provide vertical visual approach slope guidance to the runway, which is especially useful during marginal VMC or in situations where there are reduced visual cues. For example, various existing Approach Lighting Systems (ALS) provide techniques that can be used by flight crews to transition from instrument flight to visual flight in order to land. An ALS provides a directional pattern of high intensity signal lights that start at a landing threshold of the runway, and that extend a prescribed distance into the approach area. The signal lights shine upwardly toward the aircraft along the approach slope or glide path and visually guide the pilot during the approach and landing. Some ALSs include sequenced flashing lights which appear to the pilot as a ball of light traveling towards the runway at high speed. Such systems are referred to as Medium intensity Approach Lighting Systems with Runway alignment Indicator Lights (MALSR) and may enable a pilot to laterally align the aircraft with the runway.
A well known airport lighting aid is the Precision Approach Path Indicator (PAPI) system. The PAPI system uses a single row of either two or four light units installed on either side of the runway. The light units are arranged in a line perpendicular to the runway centerline to define the visual glide path angle. Each light unit has a white segment in an upper part of the beam and a red segment in a lower part of the beam, with the segments separated by a pink transition zone. In a two-light PAPI system, the lights are positioned and aimed to produce a signal presentation wherein a pilot in an aircraft that is on or close to the established approach path sees the light unit nearest the runway as red and the second light unit as white. If the aircraft is above the approach path, the pilot sees both light units as white. If the aircraft is below the approach path, the pilot sees both light units as red.
In a four-light PAPI system, the signal presentation is such that a pilot in an aircraft which is on or close to the established approach path, sees the two light units nearest the runway as red, and the two light units farthest from the runway as white. If the aircraft is above the approach path, the pilot sees the light unit nearest the runway as red, and the three light units farthest from the runway as white. If the aircraft is further above the approach path, the pilot sees all of the light units as white. If the aircraft is below the approach path, the pilot sees the three light units nearest the runway as red, and the light unit farthest from the runway as white. If the aircraft is further below the approach path, the pilot sees all of the light units as red.
The Visual Approach Slope Indicator (VAST) system is another well known airport lighting aid system. VASI system installations are typically two, four, six, twelve or sixteen lights arranged parallel to the runway centerline or as bars (commonly referred to as near, middle and far bars). Typical VASI installations can be two bars, near and far, and may include two, four, or twelve lights units. Two-bar VASI installations provide one visual glide path which is normally set at three degrees. Some VASI installations are three bars spaced intermittently along one or both sides of the runway, near, middle and far, to provide an additional visual glide path to accommodate high cockpit aircraft. Three-bar VASI installations provide two visual glide paths. The lower glide path is provide by the near and middle bars and is typically set at three degrees, while the upper glide path, which is provided by the middle and far bars, is typically one quarter of a degree higher. This higher glide path is intended for use only by high cockpit aircraft to provide a sufficient Threshold Crossing Height (TCH). VASI installations having two, four, or six light units are located on only one side of the runway and may be installed on either side. If a VASI installation includes twelve or sixteen light units, they may be located on both sides of the runway.
Another known airport lighting aid system uses a tri-color lighting technique. Typically, tri-color visual approach slope indicators are arranged as a single light unit that projects a three-color visual approach path into the final approach area of the runway. The below glide path indication is red, the above glide path indication is amber, and the on glide path indication is green.
A fourth known airport lighting aid system uses a pulsating light. The visual approach slope indicators are arranged as a single light unit that projects a two color visual approach path into the final approach area of the runway. The on glide path indication is a steady white light. The slightly below glide path indication is a steady red light. If the aircraft descends further below the glide path, the red light starts to pulsate. The above glide path indication is a pulsating white light. The pulsating rate increases as the aircraft deviates further above or below the desired glide path.
One challenge facing pilots during flight that is not addressed by the foregoing airport lighting aid systems is the pilot's need to confirm that an airport and/or a runway that is visible from the cockpit of the aircraft is the target airport and/or the target runway, i.e., the airport and runway which have been identified in the pilot's flight plan as the airport and runway at which the aircraft is scheduled to land. Locating the target airport and/or the target runway can be challenging after a long flight, or in geographic regions having multiple and/or closely located airports, or at night, or in cases where pilots become, disoriented, or task saturated, or otherwise confused. Currently, the pilot must refer to a chart comprising one or more pieces of paper that contain information about the target airport and/or the target runway. The pilot must read through the information presented there to learn what type of airport lighting aid is available at the target airport. Then, when the aircraft is close enough to allow the pilot to visually observe the airport lighting aid, the pilot looks out of the cockpit window to visually confirm that the aircraft is approaching the correct airport. This can be a relatively inefficient method of confirming that the aircraft is approaching the target airport and/or the target runway, and, though highly unlikely, could lead to a pilot landing at an incorrect airport or at an incorrect runway at the target airport. If, for example, the pilot's chart simply indicates that the target airport uses a PAPI, then it is postulated that a pilot might conclude that he is approaching the correct airport if the pilot looks out of the cockpit window and sees a runway with a PAPI. This is because many runways use a PAPI and the mere presence of a PAPI at a visible runway is not confirmation that the visible runway is the target runway.
An additional challenge facing pilots is the fact that airport and runway conditions may change during flight. For instances, the target runway or the target airport may close while the aircraft is in flight or the target airport's lighting aid may malfunction. This information will not be available in the pilot's chart. In other instances, while the information may be available to the pilot prior to departure, it is postulated that the pilot may nevertheless fail to observe the warning or may forget the information during flight.
Hett and Gannon each describe systems and methods for simulating an ALS and for displaying the simulated ALS on a display unit in the cockpit of an aircraft. In this manner, Hett and Gannon each provide a system and method to assist the pilot in staying on an appropriate glide slope during the landing phase of a flight. However, neither Hett nor Gannon provide a pilot with an indication as to whether the airport and/or runway which the pilot is approaching is, in fact, the target airport or the target runway. Nor does Hett or Gannon provide a pilot with information pertaining to changed conditions of the target airport and/or runway.
Accordingly, it is desirable to provide a system that enhances a pilot's ability to discern whether a visible airport and/or runway are the target airport and the target runway. In addition, it is desirable to provide a system that dynamically communicates conditions of the target airport and/or target runway to the pilot. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention.